The Phillies have an excellent starting catcher in Carlos Ruiz.
The back-up catcher in 2011 was Brian Schneider.
He is an anemic left handed hitter with a weak throwing arm.
Erik Kratz is an excellent defensive catcher with a strong arm.
Erik Kratz is also a strong right handed power hitter who is having a great 2012 Spring Training at the plate.
In addition, to being an excellent defensive back-up when needed, he would be very valuable as a pinch-hitter, late in games when power is needed.